• Volume 28, Issue 1

      July 1948,   pages  1-34

    • The anatomy of the vertebral column in serpentes

      Maheshwar Singh Sood

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      The author has made an intensive study ot the morphology of snake vertebræ by a careful examination of whole preparations stained with alizarin and of transverse, frontal and sagittal sections. The more important features discovered are as follows:

      1. The already recognized regions,precaudal andcaudal, of the ophidian vertebral column may be further divided into several sub-regions;viz., thecervical, thoracic, lumbar, antero- caudal, mid- caudal andposterocaudal sub-regions. The characteristics of each sub-region are dealt with.

      2. The general structure of the trunk vertebra in Serpentes is described in detail. Amongst the new features discovered may be mentioned the presence of a lateral projection on each side of the prezygapophysis which serves for the attachment of certain muscles and appears to correspond to theprocessus mammillaris of mammals, the differences in the extent and configuration of theprocessus spinosus; the occurrence of two pairs of intervertebral foramina (superior intervertebral and inferior intervertebral) on each side of the vertebral column and a pair ofintravertebral sub- central foramina.

      3. The trunk vertebræ ofEryx johni have been studied in minute detail by means of serial sections. The precise relation of contiguous vertebræ, as well as the nature of intervertebral and vertebro-costal articulations, is described. The supra-central ridge, two supra-central cavities, and the disposition of the marrow-spaces are described for the first time.

      4. The minute anatomy of the trunk vertebræ ofPtyas mucosus. Lycodon aulicus, Typhlops braminus andEnhydrina schistosa has been investigated. It is found that the configuration of the vertebra, the structure of the processus spinosus, the disposition of the marrow-spaces, the extent of the arching of one vertebra over another, the zygapophysial and zygosphenal articulations, and the occurrence (or otherwise) of the hypocentrum vary from species to species.

      5. The minute anatomy of the caudal vertebræ ofLycodon aulicus,Natrix piscator, andEnhydrina schistosa has been dealt with and the differences between the various sub-caudal regions described.

    • South Indian phycomycetes—II - Some little known species ofPythium occurring in South India

      M S Balakrishnan

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      Four species ofPythiumP. carolinianum, P. parcecandrum, P. periplocum andP. catenulatum are reported for the first time in India. The isolate ofP. periplocum obtained is considered a new variety as it produces resting spores and is named P.periplocum var.Coimbatorensis var. nov. The morphological features and peculiarities of each species are described and discussed.

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